Hayes Dominion A4 Disc Brake

With the 4-piston Dominion A4, Hayes has developed a new disc brake especially for trail, enduro, downhill and E-MTB applications.

High braking power with 4-Piston: Disc Brake Dominion A4 from Hayes

Dominion’s master cylinder is factory tuned for the shortest dead stroke possible and a crisp bite point. The Dominion A4 caliper utilizes four pistons in the most structurally rigid design possible. It features a cold-forged caliper and KingPin structural pad retention bolt that increases stiffness.

With a motorsports-inspired Two-Stroke dual port bleed system, industry-leading DOT 5.1 fluid and Kevlar hose, the hydraulic system is engineered for ultimate performance across all temperatures and easy maintenance.

Features - Dominion A4

4-Piston Caliper
Cartridge-bearings used in the brake lever
Aluminum piston operates smoothly across operating temperatures
Piston glide ring - technology pioneered in suspension forks
Patented Crosshair caliper alignment screws
Allows mechanics and end users to quickly and accurately set brake caliper with no rubbing of the rotor on the pads
Eliminates guesswork and trial and error

Product features

Use: MTB, E-Bike
Model: Dominion A4
Brake type: Disc-Brake
Lever length: 2-Finger
Open clamp: Yes
Caliper: 4-Piston
Brake mounting: Postmount
Brake pads: T106 Semi-Melalic and T100 Sintered Metalic
Brake hose length: front 1000mm / rear 1800mm (shortable)
Brake fluid: DOT 5.1
Recommended brake rotor: D-Series

Mount (choose variant)

front - left
rear - right

Material

Lever: Aluminum
Caliper: Aluminum
Piston: Aluminium for heat management

Color

black/bronze

Scope of delivery

1 Brake lever
1 Brake caliper
1 Brake hose (shortable)
1 Olive
1 Insertpin
1 pair T106 Semi-Melalic brake pads
1 pair T100 Sintered Metalic brake pads
2 Screws for brake caliper
Disc brake is ready for installation, completely assembled and bleeded!

Rotor and Adapter not included!

Hayes Dominion A4 Disc Brake front brake